﻿//fgnass.github.com/spin.js#v1.2.5
(function (window, document, undefined) {

    /**
    * Copyright (c) 2011 Felix Gnass [fgnass at neteye dot de]
    * Licensed under the MIT license
    */

    var prefixes = ['webkit', 'Moz', 'ms', 'O']; /* Vendor prefixes */
    var animations = {}; /* Animation rules keyed by their name */
    var useCssAnimations;

    /**
    * Utility function to create elements. If no tag name is given,
    * a DIV is created. Optionally properties can be passed.
    */
    function createEl(tag, prop) {
        var el = document.createElement(tag || 'div');
        var n;

        for (n in prop) {
            el[n] = prop[n];
        }
        return el;
    }

    /**
    * Appends children and returns the parent.
    */
    function ins(parent /* child1, child2, ...*/) {
        for (var i = 1, n = arguments.length; i < n; i++) {
            parent.appendChild(arguments[i]);
        }
        return parent;
    }

    /**
    * Insert a new stylesheet to hold the @keyframe or VML rules.
    */
    var sheet = function () {
        var el = createEl('style');
        ins(document.getElementsByTagName('head')[0], el);
        return el.sheet || el.styleSheet;
    } ();

    /**
    * Creates an opacity keyframe animation rule and returns its name.
    * Since most mobile Webkits have timing issues with animation-delay,
    * we create separate rules for each line/segment.
    */
    function addAnimation(alpha, trail, i, lines) {
        var name = ['opacity', trail, ~ ~(alpha * 100), i, lines].join('-');
        var start = 0.01 + i / lines * 100;
        var z = Math.max(1 - (1 - alpha) / trail * (100 - start), alpha);
        var prefix = useCssAnimations.substring(0, useCssAnimations.indexOf('Animation')).toLowerCase();
        var pre = prefix && '-' + prefix + '-' || '';

        if (!animations[name]) {
            sheet.insertRule(
        '@' + pre + 'keyframes ' + name + '{' +
        '0%{opacity:' + z + '}' +
        start + '%{opacity:' + alpha + '}' +
        (start + 0.01) + '%{opacity:1}' +
        (start + trail) % 100 + '%{opacity:' + alpha + '}' +
        '100%{opacity:' + z + '}' +
        '}', 0);
            animations[name] = 1;
        }
        return name;
    }

    /**
    * Tries various vendor prefixes and returns the first supported property.
    **/
    function vendor(el, prop) {
        var s = el.style;
        var pp;
        var i;

        if (s[prop] !== undefined) return prop;
        prop = prop.charAt(0).toUpperCase() + prop.slice(1);
        for (i = 0; i < prefixes.length; i++) {
            pp = prefixes[i] + prop;
            if (s[pp] !== undefined) return pp;
        }
    }

    /**
    * Sets multiple style properties at once.
    */
    function css(el, prop) {
        for (var n in prop) {
            el.style[vendor(el, n) || n] = prop[n];
        }
        return el;
    }

    /**
    * Fills in default values.
    */
    function merge(obj) {
        for (var i = 1; i < arguments.length; i++) {
            var def = arguments[i];
            for (var n in def) {
                if (obj[n] === undefined) obj[n] = def[n];
            }
        }
        return obj;
    }

    /**
    * Returns the absolute page-offset of the given element.
    */
    function pos(el) {
        var o = { x: el.offsetLeft, y: el.offsetTop };
        while ((el = el.offsetParent)) {
            o.x += el.offsetLeft;
            o.y += el.offsetTop;
        }
        return o;
    }

    var defaults = {
        lines: 12,            // The number of lines to draw
        length: 7,            // The length of each line
        width: 5,             // The line thickness
        radius: 10,           // The radius of the inner circle
        rotate: 0,            // rotation offset
        color: '#000',        // #rgb or #rrggbb
        speed: 1,             // Rounds per second
        trail: 100,           // Afterglow percentage
        opacity: 1 / 4,         // Opacity of the lines
        fps: 20,              // Frames per second when using setTimeout()
        zIndex: 2e9,          // Use a high z-index by default
        className: 'spinner', // CSS class to assign to the element
        top: 'auto',          // center vertically
        left: 'auto'          // center horizontally
    };

    /** The constructor */
    var Spinner = function Spinner(o) {
        if (!this.spin) return new Spinner(o);
        this.opts = merge(o || {}, Spinner.defaults, defaults);
    };

    Spinner.defaults = {};
    merge(Spinner.prototype, {
        spin: function (target) {
            this.stop();
            var self = this;
            var o = self.opts;
            var el = self.el = css(createEl(0, { className: o.className }), { position: 'relative', zIndex: o.zIndex });
            var mid = o.radius + o.length + o.width;
            var ep; // element position
            var tp; // target position

            if (target) {
                target.insertBefore(el, target.firstChild || null);
                tp = pos(target);
                ep = pos(el);
                css(el, {
                    left: (o.left == 'auto' ? tp.x - ep.x + (target.offsetWidth >> 1) : o.left + mid) + 'px',
                    top: (o.top == 'auto' ? tp.y - ep.y + (target.offsetHeight >> 1) : o.top + mid) + 'px'
                });
            }

            el.setAttribute('aria-role', 'progressbar');
            self.lines(el, self.opts);

            if (!useCssAnimations) {
                // No CSS animation support, use setTimeout() instead
                var i = 0;
                var fps = o.fps;
                var f = fps / o.speed;
                var ostep = (1 - o.opacity) / (f * o.trail / 100);
                var astep = f / o.lines;

                !function anim() {
                    i++;
                    for (var s = o.lines; s; s--) {
                        var alpha = Math.max(1 - (i + s * astep) % f * ostep, o.opacity);
                        self.opacity(el, o.lines - s, alpha, o);
                    }
                    self.timeout = self.el && setTimeout(anim, ~ ~(1000 / fps));
                } ();
            }
            return self;
        },
        stop: function () {
            var el = this.el;
            if (el) {
                clearTimeout(this.timeout);
                if (el.parentNode) el.parentNode.removeChild(el);
                this.el = undefined;
            }
            return this;
        },
        lines: function (el, o) {
            var i = 0;
            var seg;

            function fill(color, shadow) {
                return css(createEl(), {
                    position: 'absolute',
                    width: (o.length + o.width) + 'px',
                    height: o.width + 'px',
                    background: color,
                    boxShadow: shadow,
                    transformOrigin: 'left',
                    transform: 'rotate(' + ~ ~(360 / o.lines * i + o.rotate) + 'deg) translate(' + o.radius + 'px' + ',0)',
                    borderRadius: (o.width >> 1) + 'px'
                });
            }
            for (; i < o.lines; i++) {
                seg = css(createEl(), {
                    position: 'absolute',
                    top: 1 + ~(o.width / 2) + 'px',
                    transform: o.hwaccel ? 'translate3d(0,0,0)' : '',
                    opacity: o.opacity,
                    animation: useCssAnimations && addAnimation(o.opacity, o.trail, i, o.lines) + ' ' + 1 / o.speed + 's linear infinite'
                });
                if (o.shadow) ins(seg, css(fill('#000', '0 0 4px ' + '#000'), { top: 2 + 'px' }));
                ins(el, ins(seg, fill(o.color, '0 0 1px rgba(0,0,0,.1)')));
            }
            return el;
        },
        opacity: function (el, i, val) {
            if (i < el.childNodes.length) el.childNodes[i].style.opacity = val;
        }
    });

    /////////////////////////////////////////////////////////////////////////
    // VML rendering for IE
    /////////////////////////////////////////////////////////////////////////

    /**
    * Check and init VML support
    */
    !function () {

        function vml(tag, attr) {
            return createEl('<' + tag + ' xmlns="urn:schemas-microsoft.com:vml" class="spin-vml">', attr);
        }

        var s = css(createEl('group'), { behavior: 'url(#default#VML)' });

        if (!vendor(s, 'transform') && s.adj) {

            // VML support detected. Insert CSS rule ...
            sheet.addRule('.spin-vml', 'behavior:url(#default#VML)');

            Spinner.prototype.lines = function (el, o) {
                var r = o.length + o.width;
                var s = 2 * r;

                function grp() {
                    return css(vml('group', { coordsize: s + ' ' + s, coordorigin: -r + ' ' + -r }), { width: s, height: s });
                }

                var margin = -(o.width + o.length) * 2 + 'px';
                var g = css(grp(), { position: 'absolute', top: margin, left: margin });

                var i;

                function seg(i, dx, filter) {
                    ins(g,
            ins(css(grp(), { rotation: 360 / o.lines * i + 'deg', left: ~ ~dx }),
              ins(css(vml('roundrect', { arcsize: 1 }), {
                  width: r,
                  height: o.width,
                  left: o.radius,
                  top: -o.width >> 1,
                  filter: filter
              }),
                vml('fill', { color: o.color, opacity: o.opacity }),
                vml('stroke', { opacity: 0 }) // transparent stroke to fix color bleeding upon opacity change
              )
            )
          );
                }

                if (o.shadow) {
                    for (i = 1; i <= o.lines; i++) {
                        seg(i, -2, 'progid:DXImageTransform.Microsoft.Blur(pixelradius=2,makeshadow=1,shadowopacity=.3)');
                    }
                }
                for (i = 1; i <= o.lines; i++) seg(i);
                return ins(el, g);
            };
            Spinner.prototype.opacity = function (el, i, val, o) {
                var c = el.firstChild;
                o = o.shadow && o.lines || 0;
                if (c && i + o < c.childNodes.length) {
                    c = c.childNodes[i + o]; c = c && c.firstChild; c = c && c.firstChild;
                    if (c) c.opacity = val;
                }
            };
        }
        else {
            useCssAnimations = vendor(s, 'animation');
        }
    } ();

    window.Spinner = Spinner;

})(window, document);
